Triangle, read by rows, T(n,k) = k*Sum_{i=0..(n-k)/2} C(k,i)*C(2*n-k-4*i-1,n-2*i-k)/(n-2*i).

Terms

a(0) =1a(1) =1a(2) =1a(3) =3a(4) =2a(5) =1a(6) =6a(7) =7a(8) =3a(9) =1a(10) =16a(11) =18a(12) =12a(13) =4a(14) =1a(15) =47a(16) =53a(17) =37a(18) =18a(19) =5a(20) =1a(21) =146a(22) =162a(23) =120a(24) =64a(25) =25a(26) =6a(27) =1a(28) =471a(29) =518